1. Field of the Invention
The present invention relates to an electronic timepiece having a rotary annular dial which coacts with a switch input circuit for inputting data.
2. Description of the Prior Art
Conventionally, a switch input mechanism which coacts with an annular dial in an electronic watch has been a mechanism having switch pins which move up and down by means of projected and recessed portions of the annular dial and so that the switch turns ON/OFF. For example, a switch input mechanism of this type is disclosed in U.S. Pat. No. 4,451,159, issued May 29, 1984 to Tanaka.
In the conventional type of switch input mechanism using an annular dial, the maximum mode number which can be distinguished by the number of switch pins is limited. For example, when there were four switch pins, the mechanism could establish only up to 12 modes at the maximum. Generally, assuming that the number of switch pins is n, the establishable maximum mode number will be n.times.(n-1) when n.gtoreq.3. However the number of switch pins is limited to four, and it was actually impossible to increase the number of switch pins. Also, as the switch pins are arranged to move up and down by the projected and recessed portions of the annular dial, it was structurally impossible to establish more than 12 patterns of projected and recessed portions. Therefore the conventional switch input mechanism using a rotary annular dial has the disadvantage of not being able to establish more than 12 modes.